Is there a way to modify a Cox Babe .049 to use an external tank and increase the run time?

John

I am gambling that this will work, but on the Tech Terror, I have buried a tank in the nose of the plane.  I plan to have its fuel pickup go to one of the vents on the Golden Bee tank, and cap the other vent.  The engine should drain the extra tank, then its own.  We'll see if that works.

Plan B is that Kavan made a tank extender that bolts between the tank and backplate giving well over double the run time.  You may be able to find one on e-Bay or a request in the wanted/sale portion of this website.

I would vote for the Sure Start or the previous version plastic backplate made for using an external tank.  I will gladly swap you one complete backplate mount with needle valve,a good gasket and reed for your Babe Bee tank, and throw in a small Perfect brand wedge tank to hold the fuel. 
There is also a guy on E-bay who bought a bunch of Sure Starts and parted them out- he probably has a backplate-but the cost + shipping may be a bit much, don't know for sure. 
The Kavan tank extenders worked, but tended to leak, if you tightened the screws some more to stop the leak they sometimes cracked.
I would advise against drilling holes in the tank or backplate - I just don't like seeing good parts modified to do a job that other readily available parts are designed to do.

Larry,

That's a nice flying little plane. The engine appears to be a Black Widow front end on a Babe Bee tank. Runs great in the video.

George

The tank is a Perfect (now Brodak) wedge of 3/4 oz.  I have not timed it but it probably runs five to six minutes.  The fuel line connects to the nipple on the backplate inside.  I use a small piece of copper tubing as a coupling between the engine tubing and the external tank tubing.  I don't know if the front end is a Black Widow or not, but but the cylinder does have dual ports.  It runs fairly well.  I use 42' X .012's to keep from getting dizzy.  I only fly this plane one day a year, but it is definitely one of the most enjoyable planes I have.     

John, as a note,  remember to draw all the air possible out of the balloon with your syringe before filling, it will run much better!! 

Is that a Man-Win trainer you have that mounted on.  If so, you won't be disappointed.